The purpose of this application is to continue the involvement of the University of Pennsylvania as a site for the NET-PD large, simple trial of creatine (LS-1). It is well-known that there is a great need for treatments that can slow progression in degenerative disorders such as Parkinson's Disease. The goal of the LS-1 trial is to test the hypothesis that daily administration of creatine (10gm/day) is more effective than placebo in slowing clinical decline in PD between baseline and the 5 year follow-up visit in the context of a large, simple trial. The University of Pennsylvania has participated in the NET-PD consortium since its inception. In the upcoming funding cycle, we propose to continue our role as an active, successful recruiting site and a participant in the intellectual activities related t the study including review of data and participation in manuscript preparation.